Synthesis of LiNbO3 nanocrystals by microwave-assisted hydrothermal method: formation mechanism and application to hydrogen evolution reaction

Lithium niobate (LiNbO3) is an important ferroelectric material with a wide range of applications. In this work, the use of microwave radiation to improve the conditions of hydrothermal synthesis of pure nanocrystalline LiNbO3 was proposed. The structural characterization showed that nanoparticles of a pure LiNbO3 phase were synthesized. The scanning electron microscopy and transmission electron microscopy analysis revealed a high-quality nanoparticle with an average diameter of ca. 42 and 65 nm for 2 and 3 h of synthesis time, respectively. These results represent a time-saving using a microwave-assisted hydrothermal method for LiNbO3 preparation, with excellent quality at the nanometer scale. The nanoparticles were employed as photocatalysts for hydrogen evolution reaction through water splitting, reaching the rate of 10.5 mu mol h(-1) g(-1). It had shown to be a potential candidate for water photolysis due to the small particle size and high crystallinity. Moreover, it also allows the direct and fast synthesis of LiNbO3 on carbon fiber, multi-walled carbon nanotubes and nanocellulose, which were used as supporting materials for the fabrication of novel nanocomposites.